There is a key rule of thumb (or heuristic) in science known as the Copernican Principle. It essentially says: “We’re not special.” (The “we” in question being the human race.) It’s named after Nicolaus Copernicus, who, in 1543, forever banished the Earth and its thin film of humanity from the center of the universe.
Ever since, the science view of humanity is that it’s just part of the landscape, nothing particularly special, a mere consequence of energy+time creating increasing organization in systems. We may be complex, perhaps even a little surprisingly so, but we’re still nothing special.
Yet it seems to me that, at least in some ways, we really are.
To claim that we’re special (or not) demands a definition of what’s meant by special. The word itself as generally used has four possible meanings: unique, unusual, excellent, or beloved. (Can I touch all four bases? “You have special skills that make you special among your peers, and that’s why you’re specially special to me.” Gotta gimme three outta four on that at least.)
In the Copernican case special means unique or unusual. Humanity is not unique or unusual. (Many may think those two are the same thing, but I had an English teacher who was very particular that unique means there can be only one.) Our existence, my writing this post, you reading it, could happen anywhere in the cosmos.
That much is true. We believe the laws of physics are the same everywhere, so certainly the physical causes that led to us being here could have happened anywhere. In the purest sense of the Copernican principle, we’re not the center of anything.
But I think we might at least be unusual. We might even somewhat unique. (I disagreed with that English teacher.) In addition, it’s possible we’re a little excellent, too.
The former is an equation that attempts to quantify the probability of intelligent life. It contains a number of factors that combine to provide a number:
The result, N, depends on those factors, each of which is a wild guess — some wilder than others. (I’m a bit askance at the units in the equation: fractions, a rate, an average, and a timespan. Yikes.)
Astronomers, SETI researchers, and science fiction fans, have long hoped the factors allow our galaxy, the Milky Way, to be teeming with alien life. (Or at least a few, eh?) Even a single species with the right technology, if motivated to explore, could colonize the entire galaxy in under a million years.
The Fermi Paradox, in response to optimistic factor weighting that suggests a busy galaxy, asks plaintively and piteously, “Okay then, so where are they?”
One answer is that a reasonably low estimate of those factors turns up a troublingly low result. The first and last terms are numbers, respectively the rate of star production and the lifetime where a species communicates into space. (Note that the equation is tuned to produce the number of species we might hear from.)
Ignoring those numbers, the middle five terms are factors, some of them much larger than others but let’s average them out and assign odds of 1/10000 to each. That gives us:
Awfully small odds with only 2.5×1011 stars in the galaxy. Those odds make us likely the only intelligent life in the Local Group! SETI is probably wasting its time.
The unknown values of the terms in Drake’s equation, along with the weirdness of the term’s units, inspired me to a simple version based on a set of specific events that seem necessary for intelligent life. I’ve explored all this before. (See Simple Probabilities.) Here I’ll just show you the equation:
Which is pretty much the same thing as above, but here I’m estimating the odds of a single intelligent civilization arising. (And I threw in one more term, so six things with 1/1000 odds necessary for us to be here pondering this.)
Again, the point is that reasonable individual odds result in extraordinary odds overall. We seem to be, at the least, statistically special.
(I would argue that sitting here pondering these things makes us special, too, and maybe a bit excellent.)
One last consideration: We might be the first. We might be The Ancestors future species millions of years from now will be talking about in hushed voices. (Or derisive ones.)
If we grant the universe a lifetime of (at least) one-trillion years, and call that a 24-hour day, then right now, at 13.8 billion years, we haven’t quite reached 00:20 of the day. Not even twenty minutes past midnight.
Our appearance at this time might be unusual. The Earth may only be 4.5 billion years old, which says intelligent life can arise in that time, but it may take many versions of Earth over the cosmic lifetime to produce one that pulls it off.
We may be unique in time, having showed up to the party very early!
Recently I thought of another sense in which we’re a bit unique. It has to do with this chart (you may have seen a similar one somewhere):
It suddenly struck me that, being of only 4.9% of the total energy of the universe is also a bit unique. Of course, all matter we know is unique in that sense.
Even when we ignore that huge fraction of dark energy, we’re still only composed of 15% of the total. (As is, again, all the matter we know.)
Within the tiny fraction of normal matter, of six quarks, three electron types, and three neutrino types, everything we see or touch is composed of only two of the six quarks and one electron.
Let me stress this: Only three particles comprise all atoms: up quarks, down quarks, and electrons. All chemistry is largely based on just the electrons.
Further, we only experience one of the bosons (the photons).
We never experience the W-, W+, or Z0, bosons, nor do we experience the gluons or the Higgs boson. We also never experience the other four quarks, any of the three neutrinos, or the other two electrons. We do experience gravity, but currently it’s not considered a particle (the boson, the graviton, is theoretical and beyond our ability to observe).
Our entire experience of reality is based on four sub-atomic particles: Three Fermions and a Boson. Sounds like a movie title.
This doesn’t make humans special. As I say, it applies to all the matter we experience. But it struck me that normal matter is kinda special from the point of view of the universe.
Ordinary matter is pretty small potatoes to the universe. Its biggest client by far is dark energy — the ripping apart force. Dark matter — the pulling together force — is still big business, but definitely secondary. Dark energy is ultimately all that’s going to matter — the Big Darkness of Entropic Heat Death is the final act.
Compared to commerce like that, we’re a kid’s lemonade stand set up for an afternoon. (Although it may be that we’re the only lemonade stand in the city, if not the country.)
So we’re special in being so very small as well as being unique. That might even make us dear to the universe.
As an aside: Dark energy, as its name implies, seems to be a force of some kind, although we have no idea what it really is. We only know it because of its apparent effects on galaxies.
Dark matter is more of a mystery. We again only know it by its cosmological effects, and there’s currently a big controversy over whether dark matter is a particle, a family of particles, a fluid, or an extension of general relativity. Particularly vexing is failing to find any sign of a particle. As such, dark matter particles are starting to enter supersymmetry territory — windows are closing, candidates are being eliminated, it’s not looking good for WIMPs and MACHOs.
What once seemed a fringe, if not crackpot, theory — modified gravity — is now looking much more viable. The more data we gather, the more the scale seems to tilt in favor of such theories. I find the evidence increasingly compelling.
(Supersymmetry, on the other hand, is a theory that seems well past its expiration date. There has been no sign of supersymmetric particles, and with so many windows closed, remaining theories are pretty baroque.)
Finally, there is that here we are trying to figure out the universe, and that seems kinda special, too. Kinda excellent. Intelligent life seems to invent things mere physical reality doesn’t: justice, information, algorithms, literature, morality, digital watches.
We, and all life, are a major exception to the cruel tyranny of entropy, the unwinder of everything. It’s special that reality provides that simple building blocks, plus time, energy, and some natural rules, generate increasing complexity from biochemistry on up to bloggers. It’s an astonishing progression.
I can’t help but think it’s special — life is a special exception to entropy, we’re made of special stuff, and our brains are arguably pretty special.
Stay special, my friends! Go forth and spread beauty and light.